(a) Field of the Invention
The present invention relates to an apparatus and a method for controlling a clutch slip of a hybrid vehicle, and more particularly, to an apparatus and a method for controlling a clutch slip enable slipping even in a dry engine clutch having a small heat capacity by simultaneously slipping an engine clutch and a dual clutch in a hybrid vehicle mounted with a dual clutch transmission (DCT) to disperse the heat capacity.
(b) Description of the Related Art
A hybrid vehicle refers to a vehicle that efficiently combines two or more kinds of different power sources, in most cases, an engine that obtains driving force by combusting fuel (fossil fuels such as gasoline) and an electric motor that obtains driving force by battery power.
The hybrid vehicle may be formed in various structures by using the engine and the electric motor as the power source. For example, a vehicle that directly transfers mechanical power of the engine to wheels and is assisted by using the electric motor driven by electric power of the battery if necessary is called a parallel hybrid vehicle, and a vehicle that converts the mechanical power of the engine into electric power through an electric generator to drive the electric motor or charge the electric power in the battery is called a series hybrid vehicle.
In the parallel hybrid vehicle, the engine and the motor are connected to each other by an engine clutch, a dual clutch is connected to shafts of the engine and the motor, and a transmission is connected to the dual clutch.
Meanwhile, the hybrid vehicle has an EV mode in which the engine clutch is not coupled and the hybrid vehicle is driven by only the motor, an HEV mode in which the engine clutch is coupled and both the engine and the motor are driven, and a slip driving mode in which the engine clutch is not perfectly coupled in the HEV mode and a torque of the engine is transferred while rotation speeds of the engine and the motor are different from each other.
In the HEV mode, when an input speed input to the transmission as a sum of output torques of the engine and the motor by coupling the engine clutch is smaller than an idle rotation speed of the engine, in order to transfer driving force of the engine to the transmission, the engine clutch is controlled to be in a slip state, and in order to transfer a target engine torque, a hydraulic flow of the engine clutch is controlled.
However, the dry engine clutch used in the hybrid vehicle has a small heat capacity, and thus there is a high risk that the engine clutch is burned out during a slip control, and a dry engine clutch having a large heat capacity is very expensive.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.